title: Pneumococcal vaccination programs and the burden of invasive pneumococcal disease in Ontario, Canada, 1995-2011.
abstract: BACKGROUND
  In 1995, a publicly funded pneumococcal vaccination program for 23-valent polysaccharide vaccine (PPV23) was introduced in Ontario. Conjugate vaccines were authorized in 2001 (PCV7), 2009 (PCV10) and 2010 (PCV13).
  
  
  METHODS
  From 1995-2011, active, population-based surveillance for invasive pneumococcal disease (IPD) was conducted in Metropolitan Toronto and Peel Region, Canada.
  
  
  RESULTS
  6404 IPD cases were included. After PPV23 program implementation in 1995, IPD due to PPV23 strains decreased 49% in older adults prior to PCV7 introduction. Estimated PPV23 efficacy in vaccine eligible adults was 42.2% (95% CI; 28.6-53.2%). IPD incidence due to PCV7 serotypes in children <5 years decreased significantly after PCV7 authorization and before introduction of a publicly funded PCV7 program. Seven years after PCV7 program implementation, the incidence of IPD due to PCV7 serotypes decreased to zero in children and by 88% in adults, however, overall IPD incidence remained unchanged in adults. In 2011, the incidence of IPD was 4.5 per 100,000 in adults aged 15-64 and 19.9 per 100,000 in adults aged over 65 years, with 45 serotypes causing disease. Between 1995 and 2011, the case fatality rate of IPD in adults decreased 2% per year (95% CI, -0.9% to -3.2%). In multivariable analysis, predictors of mortality included older age, chronic conditions, nursing home residence, current smoking, bacteraemia, and illness due to serotypes 3,11A, 19A, and 19F.
  
  
  CONCLUSIONS
  While vaccination programs resulted in substantial public health benefits, herd immunity benefits of PCV7 were seen at low pediatric vaccination rates, and the case fatality rate of IPD has decreased, IPD will continue to be a cause of considerable morbidity and mortality in adults.
authors.affiliation: Mount Sinai Hospital, Toronto, Canada; University of Toronto, Toronto, Canada.
authors.forename: Wallis
authors.initials: W
authors.lastname: Rudnick
authors.forename: Zhong
authors.initials: Z
authors.lastname: Liu
authors.forename: Altynay
authors.initials: A
authors.lastname: Shigayeva
authors.forename: Donald E
authors.initials: DE
authors.lastname: Low
authors.forename: Karen
authors.initials: K
authors.lastname: Green
authors.forename: Agron
authors.initials: A
authors.lastname: Plevneshi
authors.forename: Roslyn
authors.initials: R
authors.lastname: Devlin
authors.forename: James
authors.initials: J
authors.lastname: Downey
authors.forename: Kevin
authors.initials: K
authors.lastname: Katz
authors.forename: Ian
authors.initials: I
authors.lastname: Kitai
authors.forename: Sigmund
authors.initials: S
authors.lastname: Krajden
authors.forename: Krystyna
authors.initials: K
authors.lastname: Ostrowska
authors.forename: David
authors.initials: D
authors.lastname: Richardson
authors.forename: Susan
authors.initials: S
authors.lastname: Richardson
authors.forename: Alicia
authors.initials: A
authors.lastname: Sarabia
authors.forename: Michael
authors.initials: M
authors.lastname: Silverman
authors.forename: Andrew E
authors.initials: AE
authors.lastname: Simor
authors.forename: Gregory
authors.initials: G
authors.lastname: Tyrrell
authors.forename: Allison
authors.initials: A
authors.lastname: McGeer
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D017281:Cost of Illness; D005260:Female; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D006801:Humans; D017589:Immunization Programs; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D009864:Ontario / Q000453:epidemiology; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000401:mortality / Q000517:prevention & control; D022242:Pneumococcal Vaccines / Q000008:administration & dosage*; D011159:Population Surveillance; D018074:Vaccines, Conjugate / Q000008:administration & dosage; D055815:Young Adult
chemical_list: C538862:13-valent pneumococcal vaccine; C414006:23-valent pneumococcal capsular polysaccharide vaccine; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D022242:Pneumococcal Vaccines; D018074:Vaccines, Conjugate
keywords: Case fatality; Invasive pneumococcal disease; Vaccination programs